Efficacy and Safety of Mechanical Thrombectomy for Anterior Circulation Large Vessel Occlusion Ischemic Stroke with Onset Beyond 24 h

Mechanical thrombectomy (MT) is the standard treatment for acute ischemic stroke patients with anterior circulation large-vessel occlusion within 24 h of symptom onset. However, evidence regarding its efficacy and safety beyond 24 h remains limited. This study aims to compare the effectiveness and safety of MT performed within 24 h and beyond 24 h after symptom onset.

We analyzed data from 1219 patients who underwent MT (1055 within 24 h and 164 beyond 24 h). To address baseline imbalances, inverse probability of treatment weighting (IPTW) was employed. The primary outcome was the 90-day modified Rankin Scale (mRS) score. Secondary outcomes included other clinical outcomes and safety outcomes (90-day mortality, symptomatic intracranial hemorrhage [sICH]). Weighted regression models were employed to evaluate the association between MT performed beyond 24 h and outcomes.

After IPTW adjustment, no significant differences in clinical or safety outcomes were observed between MT performed beyond 24 h and within 24 h. Specifically, MT performed beyond 24 h showed no statistically significant association with 90-day mRS scores (common odds ratio [cOR] 1.37; 95% confidence interval [CI], 0.96-1.94; P=0.081), mortality (RR 0.77; 95% CI, 0.36-1.64; P=0.496), or sICH (RR 2.19; 95% CI, 0.96-4.98; P=0.061).

In patients with anterior circulation large vessel occlusion treated with MT, an MT performed beyond 24 h was not significantly associated with differences in effectiveness or safety outcomes compared to MT performed within 24 h.